Key-operated calculator



Oct 2, 1951 c. F. WEBB 2,569,508

KEY-OPERATED CALCULATOR Oct. 2, 1951 C. F. WEBB KEYAOPERATED CALCULATOR2 Sheets-Sheet 2 Filed Nov. 22, 1948 INI/smog.

CHRTQPHER FRESEMCK wana Patented Oct. 2, l95l UNI TED S TAT ES PATEN TFFICE 2,569,508 KEY=OPERATED CALCULATOR Christopher Frederick Webb,London, gEngland,

assignor to Bell Punch Company Limited, London, England, a Britishcompany Applica-tion November 22, 1948, SerialNo,261,848 Ill-GreatB'rihill Decnber 2, 1947 4 Claims, l

This invention relatesto calculating machines and hasparticular-reference to the type of calculating machine in which thedriving rack is normally out of engagement with the registering wheels,for example the type of machine disclosed in my United States PatentsNo. 2,291,853,- dated August 4, 1942, and No. 2,356,714, dated August22, 1944, and in my British Patent No.- 522,721, accepted June 25, 1940.

The present invention relates to certain improvements in the type ofmachine just indicated.

In accordance with the present invention there is provided a calculatingmachine in which the movement of a key is transmitted through a chain oflinks -to a rack movable to transmit `motion to a pinion operativelyconnected to a numeral Wheel, one of the links-of the said chai-n oflinks being connected to the rack so that any movement of the said linkrelatively to the rack is solely of a pivotal nature, and being operablethrough the remaining links of the chain to impart to the said rack,when moving toward or away from its initial position of rest,arelatively slow motion. In brief, the chain of links insures that asthe quadrant rack moves from its position of rest it gradually increasesits velocity and, when making its return stroke, moves back to itsposition of rest gradually. vIn their nal movement both the quadrantrack and the pinion-connected to the numeral wheel are brought to restbefore the linksrof the chain have ceasedmoving. This arrangementinsures that upon the return of thequadrant rack to its initial positionany sudden jar is completely eliminated.

Another improvement provided in accordance with the present inventionrelates to thel provision of means whereby the numeral wheelsarenormally locked against rotation and which, when they are about to beset in motion as the result of actuation of a key, are automaticallyreleasedfrom said lock.

Hitherto in calculating machines of the Ycharacter indicated, a pinionwheel associated with the numeral wheel is arranged to engage withayieldingly controlled pawlwhich, when the pinion is set in motion as theresult of actuation of a key, yields` against the motion ofthe pinion soas to permit the same to rotate. It will be appreciated thatinsuchcircumstances the pinion is not positively locked againstrotation, but is merely held in a predetermined position` by ayieldingly controlled pawl engaging with the pinion between'two of itsteeth, but in-suchfashion will yield to such movement. Wth'a'yieldingly' controlled pawl it isnecessaryto have ar driving spring forthe pinionr of the numeral wheel much stronger rthan would be the-caseif the numeral wheel was ,not controlled by a yieldngly controlled pawl;vAccording to the present invention, ysince the pressure kon the pinionis relieved, a lighter'drivingspri-ng is required and, consequently, theoperator need not exertfsuch high pressures upon the keys `as whenayieldingly controlled pawl is used.

In accordance with `thevpresent invention there is associated with eachpinionmeans normally locking the same, positively against rotation andwhich, when a pinionis 4about to beset inmotionlas the resultl of theactuation of a key, automaticallyreleases ythefpinion. Thus the frictioninherent in any type of yieldingly controlled pawl is completely,eliminated enabling -a lighter touch of key operation to be employed.

In my British Patent No. 522,721, referred to above, there 4isdiscloseda calculating machine in which the rack is movable by a key of a bank ofkeys upwardly and during its upward stroke is maintained` out ofengagement with the pinion of the numeral-wheel. When,however, thepinion has reached the position which correspondsto the full actuationof the operated key a trip bar isy movedby the action of the said key topermit the rack,-funder.the influence of -a yielding control. to moveintov engagement with the pinionof the-numeral wheel. In thatarrangementthe operated key directly engages with abar whichextendslongitudinally through each column of the machine and which, upon theactuation of the :key, swings Athe bar in a direction transverse to thenormal direction ofathe rack as it moves intoengagement with the pinionsoas to `permit'acatch to move downwardly in a slot formed m a1 memberconnectedto the rack so that the rackisthen free to move under the saidyielding control into engagement with the pinion of the numeral wheel.Thus it will be seerr that theca'tch moves1 transversely tor the linekof vmovement 'of the rack lbythe l'inc'ki'ng movement of' thetrip baractuated by the "key and exact adjustment isrequired lo-synchronis themoment of releasing the" trip' bar by' the key with the arrest' ofthemechanism, andy ity is'an object of the invention to accomplishht'herelease without this .exact relation.y Furthermore, the release ofthecatch referred to onlyl takes place at the Avery bottom ofthe keystroke therethat when the numeral Wheelismovedthe pawl 66' byintroducingfafrather'harsh-operation, and it 3 is a further object ofthe invention to eliminate, or at least greatly to reduce, thisharshness.

In accordance with the present invention, upon actuation of a key, atrip bar is movable in a longitudinal direction so as to release acatch, and such release is effected directly by the mechanism and onlythrough the medium of the key stem.

The objects of the present invention relate to the attainment of theends above indicated. These general objects as well as objects relatingto details of construction and operation will become apparent from thefollowing description read in conjunction with the accompanyingdrawings, in which:

Figure 1 illustrates in vertical section the devices associated with onebank of keys of a machine of the type described; and

Figure 2 is a diagram particularly illustrating the actuation of therack controlling linkage above referred to.

As will be evident from reference to the prior patents mentioned above,the machine is of the general type disclosed therein and there are notherein detailed those elements of the complete machine which are knownto the art through the disclosure of said patents, the disclosure beingconfined to those devices which include the improvements embodying thepresent inventions.

The bank of keys 2 illustrated in Figure 1 have associated with them akey bar I, the movement of which is transmitted through a chain of links3, 4, 5, E and 'I to a quadrant rack 8 movable to transmit motion indegree related to the operated key to drive a pinion 9 connected to anumeral wheel I8. The link 1, of the said chain of links, is connectedto the quadrant rack 8 so that any relative movement between thequadrant rack 8 and the link I is solely of a pivotal nature. The link'l irs operable through the remaining links of the chain to impart tothe quadrant rack 8 a velocity which increases from zero. The returnmovement of the quadrant rack 8 to its position of rest is also effectedgradually, thus insuring that the quadrant rack 8 is provided, both atthe commencement of its movement and at the end thereof, with arelatively slow motion which reduces the inertia of the quadrant rackand the numeral wheel 9 to a minimum and assures the smooth and gradualarrest thereof.

When a key 2 is depressed an abutment thereon engages with the key bar Ito move the same downwardly. The key bar l is connected at substantiallythe ends thereof to a bell crank lever II pivoted at IIa on a fixedtransverse pin and to a link 4 which is shaped as a bell crank lever.`lIhe construction is such that as a key is moved downwardly the key barmoves downwardly and inwardly as described in said patents. As the keybar I moves downwardly it imparts through rthe pins of links 3 to 1,inclusive, to the quadrant rack 8 a motion which will be morespecifically set out in describing Figure 2. It will be observed thatthe link 3 is pivotally connected to both the key bar I and the link 4by pivot pins I2 and I3. The link 4 is pivotally mounted uponl a Xed pinI5 which extends the entire breadth .of the machine, and is common tothe various key orders thereof. The end of the link 4, remote from thatwhich is connected to the link 3, is pivotally connected to the link 5which in turn is pivotally connected to a point intermediate the lengthof the link 6 which is shaped as a. bell crank lever. The upper end ofthe link 6 is pivoted upon fixed spindle I5 whichextends through theentire breadth of the machine. The lower end of the link 8 is pivotallyconnected to the link 'I which in turn is connected through a pivot pinto the quadrant rack 8 so that the only movement of the link 'Irelatively to the quadrant rack 8 is a pivotal movement, therebyavoiding any sliding movement oi the pivot in a cam groove as disclosedin Patent No. 2,356,714.

Referring specically to Figure 2, there is diagrammatically illustratedthe operation of the chain of links as the key 2a carrying the numeral 9is depressed to move the quadrant rack 8 from its position of restthrough its complete movement of nine teeth. An arm 4a of the link 4 isshown pivotally connected at A1 to a selector bar Il. As the key 2a ofthe series of keys 2 is operated it moves, through the medium of thebell crank levers II and 4, the selector bar I'I through the positionsmarked A, B, C, D and E. As the selector bar is moved through thesepositions the pivot pin of the arm 4a moves through the positions A1,B1, Ci, Di and E1 and the free end of the link 4, shown as pivotallyconnected at A2 the link 5, moves through the positions A2, B2, C2, D2and E2, While the end of the link 5 which is shown as pivotallyconnected at A3 to the link 6 moves through the positions A3, B3, C3, D3and E3. The movable end of the link 6 is pivotally connected at A4 tothe link 'I and moves through the positions A4, B4, C4, D4 and E4 whilethe link l which is pivotally connected at A5 to the quadrant rack 8does not move at all during the initial movement of the other links fromtheir A to their "B positions, after which the end of the link 'I whichis pivotally connected to the quadrant rack 8 takes up the successivepositions C5, D5 and E5. The initial positions A5 and B5 are coincident.As the link 'l moves so that the quadrant rack 8 is moved the successivepositions of the first tooth are those indicated at A6, Be, Cs, De andE6, As and Be being coincident.

It will be observed that during the operation of the machine the upwardmovement of the rack may be arrested by the appropriate key at any toothposition from one to nine, this being controlled by the co-operation ofkey stems with the bars I and I'I, as disclosed in said prior patents.At any of such positions the connection of the link 'I with the link 6becomes temporarily a stationary point about which the link l can swingto permit the quadrant rack 8, when released, to move into mesh with itspinion 9. It should further be noted that at any one of the said ninepositions the link 'I will insure that the tooth engagement of thequadrant rack 8 with the pinion 9 is in a substantially radial directionrelatively to the pinion 8.

It will be observed from the above that upon the initial movement of thekey the operator merely sets the cha-in of links which is to operate thequadrant rack 8 into motion, without effecting any movement of the rack8 itself, after which the quadrant rack 8 is moved to an accelerateddegree. Referring to Figure 1 it will be observed that the main springI8 is anchored to a lateral extension 4b of the link 4, the arrangementbeing such that shortly after the movement of the link has commenced theanchorage point of the extension 4b of the link 4 rises so as to causethe effective leverage of the tension spring I8 about the pivot A1 todiminish as the tension of the spring I8 increases. The arrangement ofthe link 4 and extension 4b thereof is designed to produce asubstantially constant resistance to the pressure *of `r`the operatorsng'er throughout 'an operating stroke. If the yconnection between thelink 'I and the quadrant rack is cfa purely pivotal lcharacter, frictionis minimised Lascentrasted with that involved in a sliding -pin -a-nd jslot.

Upon the completion of akey'stroke the Vquad'- rant rack A8 is releasedby the trip mechanism -as hereinafter described and is moved under theiniluence of the drivingspring AI8 intoen'gagem'ent with the pinion 9,this being effected through the pivotal connection `of the rack to thelever 1|9 to which the rear end 1of the spring -issecured v -As Tthelquadrant rack returns to its y'positio'r-ifofrest under the iniiuenceof the -spring A)I8 `and itl-1ere- 'fore returns the pinion y9 `and thenumeral wheel l0 to their positions 'of -rest it arrives at such -aposition of rest before the chain of lin-ks formi-ng the operativeconnection between the vquadrant rack and the key bar have ceasedmoving, Consequenty, it is insured that the numeral `wheel I0 and itspinion 9 are stationary before the -mechanism effecting the withdrawalof the rack from the pinion -9 is brought into operation.

Associated with each pinion 9 there isa pawl 2| and locking lever 22.This arrangement ynormally locks the pinion 9 against rotation, and anarrangement is provided which, when-a'pinion 9 of a bank of keys isabout to beset in motion as the result of actuation of ya key,automatically releases the pinion. The pinions 9 are released eitherwhen the rack 8 positively moves the pinion or when a transfer mechanism23 rotates through the mediumfof pins 23a a toothed Wheel 24 connectedto the pinion 9. This transfer mechanism is disclosed -in Patent No.2,291,853, and need not be described in detail except to the extent ofreference to the pins 23a.

First, dealing with the instance Where the pinion '9 is moved by therack 8 it will be evident that when the trip mechanism describedhereafter releases the rack 8 the lever 22 is moved in acounterclockwise direction about its pivot-21 by the flexing of a spring28 connected between it and the lever I9. By this-action the lever v22is moved downwardly and out of engagement with the locking surface 29with which it normally engages. The pawl 2| released from its positivelocking engagement with the pinion 9 permits the numeral wheel to befreely rotated. Due to the fact that the pawl 2| is not of a yieldinglycontrolled type which snaps into and out of engagement with the tooth ofthe pinion 9 the operation of the numeral wheel is rendered less noisythan in the case of a pinion wheel which is restrained by a yieldinglycontrolled pawl.

When -a numeral Wheel of a lower order is transferring to a numeralwheel of a higher order the pins 23a are arranged to engage with theright hand lateral extension 22a of the locking lever 22 to swing thesame in a clockwise direction about its pivot 21 so as to move thelocking lever out of engagement with the locking surface of the pawl 2I. After the transfer action has taken place the pawl again becomeslocked in the position indicated, this being insured by contact of pin23a with the left hand extension 22a of the locking lever.

It has been shown that the numeral pinions are yalways positively lockedexcept when an adding or transferring operation is in progress, but itwill be appreciated that it is also necessary to remove any obstructionfrom the path of the pinions during a cancelling operation in order topermit the numeral wheels to be returned to fzero. For this vpurposethere-may be 4provided ymeans for `displacing .by Amanual operation of.a 'cancel lever all of the pawls 2| in the vaxial di- 'rectionof thepinions 9 so that the pawls 2| are temporarily moved yout of the path ofthe vpinions '9 Without in kany Way interfering with the lockingfunctions already described. A spring v2|at is arranged to exert aslight torque on the pawl 2| 'inan axial direction to return the tip ofthe pawl :into theplane of the pinion following a cancelling operation.

It will be seen that according to the present invention there isprovided a calculating machine inwhioh the pinions ofthe numeral wheelsare normally locked positively against rotation, and `wherein thearrangement is such that when the pinion wheels :are about to be set inmotion the positive lock isreleased and the pinion Wheels are free to berotated eliminating all friction and en- :abling a lighter key touch tobe employed in View "of `the fact that the driving spring YI8 need notvbe as strong as would be the case if a yieldingly controlled pawl wasemployed.

After the rack 8 has moved free of the pinion tothe degree determined bythe key which has been operated, it mustbe permitted to engage thepinion and this action is effected upon full depression of the key. Thelower end of a key stem, when it reaches the position indicated indotted lines `at 2b, is yadjacent one of the projecting lugs 32 formedon a trip bar 33. When .the key stem reaches the dotted -position atooth of the bar will have reached the face of the key at 2b and at thesame time, a groove 2c formed small amount, whereby the lug 32 and thetrip bar 33 are moved from right to left as viewed in Figure l. Thismovement of the trip bar 33 swings catch lever 34 pivotally mounted at35 about this mount so as to move the end 33 thereof out of engagementwith a tongue 31 carried by :the lever |9 which at pivot point 3| isconnected `to the rack 8. When the catch lever 34 is released from thetongue 3l the spring I8 urges the rack in a direction toward the pinion9 of the numeral wheel lll.

It will be noted that the lever I9 is released by the roller 20 on thebar when a key is depressed, and that this same roller effectsdisengagement of the rack 8 from the pinion 9 by its action on the leverI9 when a key is released to its uppermost position.

Thus it will be seen that the movement oi the bar of the mechanism, inresponse to the depression of a key, causes the release of catch 36Without direct vertical contact of the end of the key stern as formerlyrequired, and in ordinary operation the trip is effected by the momentumof the mechanism without direct influence from the key. Such anarrangement practically eliminates that harshness introduced by the deadend stroke operation inherent in the arrangement described in saidBritish Patent No. 522,721.

What I claim and desire to protect by Letters Patent is:

1. In a calculating machine of the type referred to having a pluralityof keys, a member movable to an extent variable in dependence upon thekey actuated, a rack, a pinion adapted to be driven by said rack, anumeral wheel connected to said pinion, and a linkage connecting saidmember and said rack to drive the rack.

'said linkage including a pair of links, one end of each of the linksbeing pivotally joined together, the opposite end of one of the links ofthe pair being pivoted to said rack, the opposite end of the second linkof the pair being pivoted about a nxed point, and the second link of thepair being actuated by an adjoining portion of the linkage connected tosaid member, the link-age being constructed and arranged to impart tothe rack a relatively slow motion when the rack is moving towards oraway from its position of rest.

2. In a calculating machine of the type referred to having a pluralityof keys, a member movable to an extent variable in dependence upon thekey actuated, a rack, a pinion adapted to be driven by said rack, anumeral wheel connected to said pinion, and a linkage connecting saidmember and said rack to drive the rack, said linkage including a pair oflinks, one end of each of the links being pivotally joined together andthe opposite end of one of the links of the pair being pivoted to saidrack and the opposite end of the second link of the pair being pivotedabout a xed point, and a link joining said member to the second link ofthe pair, the linkage being constructed and arranged to impart to therack a relatively slow motion when the rack is moving towards or awayfrom its position of rest.

3. In a calculating machine of the type referred to having a pluralityof keys, a member movable to an extent variable in dependence upon thekey actuated, a rack, a pinion adapted to be driven by said rack, anumeral wheel connected to said pinion, and a linkage connecting saidmember and said rack to drive the rack, said linkage including a pair oflinks, one end of each of the links being pivotally joined together, theopposite end of one of the links of the pair being pivoted to said rack,the opposite end of the second link of the pair being pivoted about afixed point and the second link of the pair being actuated by anadjoining portion of the linkage connected to said member, the linkagebeing constructed and arranged to impart to the rack a relatively slowmotion when the rack is moving towards or away from its position ofrest, said linkage including a pivotally mounted membei' and a springfor driving said rack connected to said pivotally mounted member, theconnection being such that as the pivotally mounted member rotates aboutits pivot the eiective leverage distance of the spring from the pivotdecreases as the spring tension increases so as to oier substantiallyconstant resistance to the pressure of the operators finger in actuatinga key.y

4. In a calculating machine of the type referred to having a pluralityof keys, a member movable to an extent variable in dependence upon thekey actuated, a rack, a pinion adapted to be driven by said rack, anumeral wheel connected to said pinion, and a linkage connecting saidmember and said rack to drive the rack, said linkage including a pair oflinks, one end of each of the links being pivotally joined together, theopposite end of one of the links of vthe pair being pivoted to saidrack, the opposite REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,301,073 Mays Apr. 15, 19191,417,924 Koronski May 30, 1922 1,637,827 Kottmann Aug. 2, 19271,700,057 Johnson Jan. 22, 1929 1,761,431 Degener June 3, 1930 1,983,945Petter Dec. 1i, 1934 2,033,087 Avery Mar. 3, 1936 2,356,714 Webb Aug.22, 1944

